/*
* Copyright (C) 2008 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.android.emailcommon.mail;
import com.android.emailcommon.service.SearchParams;
import com.google.common.annotations.VisibleForTesting;
public abstract class Folder {
public enum OpenMode {
READ_WRITE, READ_ONLY,
}
public enum FolderType {
HOLDS_FOLDERS, HOLDS_MESSAGES,
}
/**
* Identifiers of "special" folders.
*/
public enum FolderRole {
INBOX, // NOTE: The folder's name must be INBOX
TRASH,
SENT,
DRAFTS,
OUTBOX, // Local folders only - not used in remote Stores
OTHER, // this folder has no specific role
UNKNOWN // the role of this folder is unknown
}
/**
* Callback for each message retrieval.
*
* Not all {@link Folder} implementations may invoke it.
*/
public interface MessageRetrievalListener {
public void messageRetrieved(Message message);
public void loadAttachmentProgress(int progress);
}
/**
* Forces an open of the MailProvider. If the provider is already open this
* function returns without doing anything.
*
* @param mode READ_ONLY or READ_WRITE
* @param callbacks Pointer to callbacks class. This may be used by the folder between this
* time and when close() is called. This is only used for remote stores - should be null
* for LocalStore.LocalFolder.
*/
public abstract void open(OpenMode mode)
throws MessagingException;
/**
* Forces a close of the MailProvider. Any further access will attempt to
* reopen the MailProvider.
*
* @param expunge If true all deleted messages will be expunged.
*/
public abstract void close(boolean expunge) throws MessagingException;
/**
* @return True if further commands are not expected to have to open the
* connection.
*/
@VisibleForTesting
public abstract boolean isOpen();
/**
* Returns the mode the folder was opened with. This may be different than the mode the open
* was requested with.
*/
public abstract OpenMode getMode() throws MessagingException;
/**
* Reports if the Store is able to create folders of the given type.
* Does not actually attempt to create a folder.
* @param type
* @return true if can create, false if cannot create
*/
public abstract boolean canCreate(FolderType type);
/**
* Attempt to create the given folder remotely using the given type.
* @return true if created, false if cannot create (e.g. server side)
*/
public abstract boolean create(FolderType type) throws MessagingException;
public abstract boolean exists() throws MessagingException;
/**
* Returns the number of messages in the selected folder.
*/
public abstract int getMessageCount() throws MessagingException;
public abstract int getUnreadMessageCount() throws MessagingException;
public abstract Message getMessage(String uid) throws MessagingException;
/**
* Fetches the given list of messages. The specified listener is notified as
* each fetch completes. Messages are downloaded as (as) lightweight (as
* possible) objects to be filled in with later requests. In most cases this
* means that only the UID is downloaded.
*/
public abstract Message[] getMessages(int start, int end, MessageRetrievalListener listener)
throws MessagingException;
public abstract Message[] getMessages(SearchParams params,MessageRetrievalListener listener)
throws MessagingException;
public abstract Message[] getMessages(String[] uids, MessageRetrievalListener listener)
throws MessagingException;
/**
* Return a set of messages based on the state of the flags.
* Note: Not typically implemented in remote stores, so not abstract.
*
* @param setFlags The flags that should be set for a message to be selected (can be null)
* @param clearFlags The flags that should be clear for a message to be selected (can be null)
* @param listener
* @return A list of messages matching the desired flag states.
* @throws MessagingException
*/
public Message[] getMessages(Flag[] setFlags, Flag[] clearFlags,
MessageRetrievalListener listener) throws MessagingException {
throw new MessagingException("Not implemented");
}
public abstract void appendMessages(Message[] messages) throws MessagingException;
/**
* Copies the given messages to the destination folder.
*/
public abstract void copyMessages(Message[] msgs, Folder folder,
MessageUpdateCallbacks callbacks) throws MessagingException;
public abstract void setFlags(Message[] messages, Flag[] flags, boolean value)
throws MessagingException;
public abstract Message[] expunge() throws MessagingException;
public abstract void fetch(Message[] messages, FetchProfile fp,
MessageRetrievalListener listener) throws MessagingException;
public abstract void delete(boolean recurse) throws MessagingException;
public abstract String getName();
public abstract Flag[] getPermanentFlags() throws MessagingException;
/**
* This method returns a string identifying the name of a "role" folder
* (such as inbox, draft, sent, or trash). Stores that do not implement this
* feature can be used - the account UI will provide default strings. To
* let the server identify specific folder roles, simply override this method.
*
* @return The server- or protocol- specific role for this folder. If some roles are known
* but this is not one of them, return FolderRole.OTHER. If roles are unsupported here,
* return FolderRole.UNKNOWN.
*/
public FolderRole getRole() {
return FolderRole.UNKNOWN;
}
/**
* Create an empty message of the appropriate type for the Folder.
*/
public abstract Message createMessage(String uid) throws MessagingException;
/**
* Callback interface by which a folder can report UID changes caused by certain operations.
*/
public interface MessageUpdateCallbacks {
/**
* The operation caused the message's UID to change
* @param message The message for which the UID changed
* @param newUid The new UID for the message
*/
public void onMessageUidChange(Message message, String newUid) throws MessagingException;
/**
* The operation could not be completed because the message doesn't exist
* (for example, it was already deleted from the server side.)
* @param message The message that does not exist
* @throws MessagingException
*/
public void onMessageNotFound(Message message) throws MessagingException;
}
@Override
public String toString() {
return getName();
}
}